Flood maps published by the Environment Agency are so inaccurate that they are significantly distorting house prices, homeowners have claimed.

Bisham and Marlow flood warden Mike Post has been fighting since 2014 to have the maps redrawn after they showed whole rows of homes besieged with water, when none had been affected in the storms of that year or 2003.

The map of the Berkshire and Buckinghamshire villages also currently includes details of a deluge in 2002 that never happened and places businesses and churches within the Thames flood zone, even though they remained dry.

“This preposterously inaccurate map includes many, many features which demonstrably did not flood such as my own house and garden,” said Mr Post.

“The map incorrectly shows whole swathes of Bisham and Marlow as being within the 2014 flood outline. The map has a whole area of fields underwater which was not the case.

“In addition the 2003 flood outline is still in error, wrongly showing properties which did not flood whilst excluding properties which did.

When Mr Post contacted the Environment Agency in 2014 the organisation agreed to change the maps, claiming he had a ‘valid point.’

He was also back by Theresa May's office, as Bisham is part of the Prime Minister's constituency. But despite admitting the error, nothing had altered when they were redrawn in 2015.

The Environment Agency bases much of its data on laser-mapping, which uses aerial scans to record the topography of the area. However locals claim that the method does not paint an accurate picture of what happened on the ground.

At a meeting of the Royal Borough of Windsor and Maidenhead Flood Liaison Group this week, residents of Wraysbury, Cookham and, Datchet in Berkshire also complained that their maps were grossly inaccurate.

Aerial shots show no water in Bisham at premises including the sports centre, even though the map shows they floodedCredit: Mike Post

The area is home to Andrew Strauss, the former England cricket captain and television presented and naturalist Steve Backshall.

Mr Post added: “It is quite clear that in the case of Bisham and Marlow, the Environment Agency is incapable of using Lidar technology effectively.

“It is absolutely unacceptable for the Environment Agency to publish false information on flooding and to leave it in the public domain.

“Can we be sure that the false historic flood information has not also been published with similar gross errors all over the country? The Historic Flood Map should be withdrawn immediately.”

A picture showing the bottom of Mr Post's lane at the peak of flooding. Water never reached his house Credit: Mike Post

The Environment Agency said the maps used to computer modelling to represent the ‘worst case scenario’ but has agreed to update the 2003 flooding data and said a review of laser-mapping data is underway to make sure the maps are accurate.

An Environment Agency spokesperson said: “Marlow has a long history of flooding, which is why we are working with local councils to build an £8 million flood scheme to protect hundreds of homes in the town.

“We update our flood risk maps every three months with the best available data and use them as part of our planning – but final decisions about where we build new flood schemes are made with the local community, taking into account other potential sources of flooding.”